Displacement flow and mixing of fluids occur in many operations present in the construction and completion of oil & gas wells e.g. primary cementing, drilling, gravel-packing, hydraulic fracturing. Over the past many years oil prices have increased significantly as a result of a diminishing supply of oil and gas from easily accessible reservoirs coupled with an increased demand due to population and consumption growth. Inevitably, there is a tendency towards deeper wells offshore and towards more challenging wells onshore. Many oil and gas wells required are long and are inclined anywhere from vertical to fully horizontal. This range of wells brings new challenges, a wider range of fluids used in the processes and additional higher risks as operational failures can become highly expensive and catastrophic. Different approaches were employed in an integrated fashion to tackle the problem in this book namely experimental, computational and analytical. The aim is to understand the displacement flows that are present in well operations and thus improve the well construction process.
This books studies an important class of fluid dynamics known as displacement flows. These frequently occur in chemical and food processing, in waxy crude oil pipeline restart flows, and in the transport of mined slurries and pulp. The defining characteristic is the displacement of a fluid by a second fluid having a greater density. We integrate experimental, analytical and computational methods to study displacement flows in slightly inclined pipes and channels. This was primarily motivated by the flows that occur during oil and gas well construction, particularly primary cementing: a process by which cement is pumped into a well to seal it by displacing the drilling mud. During this process, fluid mixing or bypassing results in cement contamination, which compromises the seal. This has very serious environmental and safety consequences if fluids leak. For example, in April 2010, the Macondo well explosion took the lives of 11 workers, and released approximately 5 million barrels of oil into the Gulf of Mexico; the immediate cause was failure of the primary cementing operation. We study and analyse the fluid dynamics behind the primary cementing operation.
An investigation of the jet trajectories and mixing behaviour of venturi-jet mixers to mix incompressible fluids in which turbulent jet injects fluid at an arbitrary angle have been studied experimentally and numerically by writing conservation equations in natural coordinate system and also by using FLUENT CFD code. Numerical results of an incompressible cross flow-jet mixing in venturi-jet mixers are presented and validated against experimental results. The effect of jet injection angle, cross flow Reynolds number and velocity ratio on entrainment and mixing of jet with incompressible cross flow in venturi-jet mixer were analysed. Twenty five cases were studied, including 5 different initial injection angles 45o, 60o, 90o, 120o, 135o and 25 different jet momentum ratios to evaluate the entrainment of jet and mixing performances of the mixer.
The ideal MHD equations consist of the continuity equation, the Cauchy momentum equation, Ampere's Law neglecting displacement current, and a temperature evolution equation. As with any fluid description to a kinetic system, a closure approximation must be applied to highest moment of the particle distribution equation. This is often accomplished with approximations to the heat flux through a condition of adiabaticity or isothermality.
The product distribution of a fast chemical reactions introduced by Bourne in 1987 was used to study mixing on T-jets reactors under different operational parameters and for different geometries. The Bourne?s test system was the reaction between 1-naphthol and diazotized sulfanilic acid. The results obtained for the mixing characterization study on T-jets using the Bourne?s test system showed that the Reynolds number has a great influence on the mixing degree. Moreover, the geometrical parameters of T-jets also influenced the conversion of Bourne’s test reactions. With increasing of ratio between the width of inlet jet and width of mixer chamber, the quality of the mixing is increasing. Another important operational parameter is the ratio of flow rates between the jets, which was also proved in this work to have a critical influence on mixing.
Odisha in the process of development has been experiencing the grim truth of displacement due to increasing development projects in recent years. Given huge stock of natural resources and investor friendly policy of Odisha government, the state has become an attractive investment destination for MNCs, both foreign as well as domestic. An attempt has been made in this Book to provide an overview of displacement and resistance with particular focus on Odisha.
The concept of development-induced-displacement is not new in Indian context. However, the topic has received wider academic and policy attentions in the past three decades in the country. Researchers argue that both women and men experience the development process and its positive and negative outcomes differently whereas the policy concentration is on the formulation of an egalitarian development programme for all sections of India. This dissertation analyses the differential DID impacts on both men and women of indigenous communities and the existing gaps in the Indian Government’s rehabilitation and resettlement programmes. Why and how the indigenous community is different from others and why does DID impacts their lives and livelihoods differently has been discussed throughout this work.
Peace, conflict and displacement are key issues in the world in general and in Africa in particular, where internal conflicts have torn whole countries apart. Literature as a form of human artistic expression has over generations dealt with the themes of exile and displacement. Exile seems to be always a part of the human condition and so creative artists inevitably return to this theme. One way through which creative literature engages this pertinent human issue is through narrative. Narration as an activity of human consciousness is a medium for understanding human experience since it articulates sequence, thereby placing events in a framing context. This book focuses on the narratives of refugee children in Kenya (Nairobi and Kakuma Refugee Camp), investigating the children’s perception of peace, conflict and displacement. In this regard, narratives told by refugee children are analyzed with the broad aim of finding out what these narratives reveal about the children’s perception of their refugee experience.
The term code-mixing refers “to all cases where lexical items and grammatical features from two languages appear in one sentence”. The current study examines the pattern of code-mixing that appears in the Pashto speech community.The present research investigates the influence of social factors on English code-mixing in Pashto language. First the focus of the study lies on the social factors e.g. style, interlocutors, topic, social distance, social status, and identity etc. and their influence on English code-mixing in Pashto language. The results show that, interlocutors, education, topic, context, profession and prestige etc. are the leading social factors which influence English code-mixing in Pashto language. The dominant pattern of code-mixing is insertion with nouns the most frequent code-mixing item. The study also concludes that Pashto is the dominant language of communication and used as a symbol of solidarity and social marker in Pashto speech community. This study contributes to the ever growing field of research on English code-mixing and establishes insertion as dominant pattern of English code-mixing in Pashto language.
Code-switching and code-mixing are the widely accepted phenomena in the everyday life of bilinguals. Pakistani English novels in which Pakistani speech communities and characters are depicted are the examples of these instances. The sociolinguistics types, reasons and context of the code- switching and code-mixing done by the characters are traced down in this work which proves that sociolinguistics theories are not only applicable to real life situations but also on the written representation of such situations by competent authors.
Economic affluence of a country is contingent with sustainable uses of its natural resources. Different governments are considering the various sources of energy to realize their supply of demand for producing electricity. A development project can only go forward if the project is developed in a sustainable manner. This book, based on Phulbari Open-pit Coal Project in Bangladesh, examines various patterns of coal mine development from the point of view of environmental justice and human rights paradigms. An open-pit mine needs a large scale displacement of local people from their agricultural lands which leads to violation of human rights and securities. The book identifies the recognition of indigenous communities of the area and their participation in decision making were severely ignored. This research based book attempts to delineate the economic and political interests prevalent both within the government and the MNC by analyzing the neo-liberalism discourse within this context. The analysis of this book should help researchers who are working on environmental justice, energy and indigenous people’s rights issues or anyone else who are may be considering it is important.
In this work, physics of complex gas-liquid flow in bubble column reactor where the interactions are not well understood is investigated experimentally using Particle Image Velcoimetry (PIV) and computationally through Euler-Eulerian & Euler-Lagrangian CFD simulations. Further, (i) multiple reaction (consecutive - competitive) (ii) acid -base mixing (iii) uric acid electrolysis and (iv) effect of surfactant on hydrodynamics of gas-liquid flow in bubble column reactor is investigated.
A brief description about field responsive fluids and their properties are described. Magnetorheological (MR) fluids are liquid materials whose properties can be controlled by the execution of an external magnetic field. These rheological changes are reversible and dependent on the strength of an excitation magnetic field. In this book, customized test equipment was constructed and fabricated, while the magnetic circuit design was analyzed using finite element method. The equipment was capable of varying the magnetic field strengths. Combinations of process parameters of initial gap size, applied current and squeeze speed were used in the experiments. Results, mainly in terms of stress-strain relationships were presented and discussed. In addition, the behaviour of MR fluids was found to be dependent on the relative movement between the solid magnetic particles and the carrier fluid in squeeze mode. Eventually, the understanding of the behaviour of such fluids, together with recent progress in the development of MR fluids, has convinced researchers and engineers that MR devices are among the most promising devices for a large number of applications in various technological fields.
Inflows into reservoirs from sidearms may contain nutrient and/or pollutant particles, which are dispersed across water bodies by various transport and mixing processes including those driven by natural convection. Understanding the particle transport in reservoirs is critical as it is directly relevant to the water quality in these water bodies. This book, therefore, involves an investigation of two major themes: natural convection and particle transport in reservoirs. In reservoirs, natural convection is induced by the ambient thermal forcing including air temperature variation and solar radiation, whereas particle motion involves several fluid dynamical processes. Accordingly, understanding of the unsteady natural convection as one of the important transport mechanisms which drives particle motion in reservoirs is of great interest. The research is to understand and quantify particles transport in a reservoir model under the influence of natural thermal forcing, and should be useful to those environmental/fluid engineering professionals who want to model and understand the transport mechanism of pollutant in natural water bodies.